Torrents of underground water from the heart of the Mojave Desert flow into Las Vegas casino waterfalls, fountains, lagoons and wave machines - an example of water use that is sucking America dry, according to one of the world's leading water authorities.

And Australia too faces the threat of over-exploitation of precious groundwaters in an arid land, says Robert Glennon, Professor of Law at the University of Arizona and author of the book Unquenchable: America's Water Crisis and What to do About it.

Professor Glennon will be at The University of Western Australia this evening to give a free public lecture: "America's Water Crisis and What to do About it: Trepidation and Inspiration for Western Australia".

He is in Australia as Distinguished Guest Lecturer for the National Centre for Groundwater Research and Training and is a Visiting Professor at UWA.

The growing number of wells tapping underground waters that have taken centuries to accumulate is a recipe for disaster as cites, mines, industry, the environment and farmers compete for dwindling resources, Professor Glennon warns.

"Our water woes will get worse before they get better because we are slow to change our ways and because water is an overlooked resource," he said.

"For example, Washington's love affair with biofuels will turn to heartbreak once America realises how many thousands of litres of water are required to produce a single litre of fuel. In Minnesota - the ‘Land of 10,000 Lakes' - a local ethanol plant is already sucking local wells dry."

Professor Glennon warns there are no quick fixes for this problem. Towing icebergs, desalination and diverting rivers are stopgaps that will not solve overexploitation.

"I'm arguing instead we need a market-based system that values water as a commodity and a fundamental human right. That is a path on which Australia has already advanced as both Australia and the US struggle with overuse of a scarce natural resource."

WHAT: Free public lecture: "America's Water Crisis and What to do About it: Trepidation and Inspiration for Western Australia"